PROCESS FOR ENZYMATIC DECOMPOSITION OF RECOMBINANT PROTEINS BY MEANS OF IGA-PROTEASE, FUSED PROTEIN, RECOMBINANT DNA, CELL

摘要

A method is claimed for prepg. proteins or peptides without a terminal methionine gp. from peptides and proteins with the sequence Met-Y-X-Pro-A (I), where X = Thr, Ala or Ser; Y = an amino acid sequence contg. at least two residues, which ends with the sequence Pro (or when X = Ser) can end with Pro-Ala-Pro; A = a further amino acid sequence. The method involves transforming a prokaryotic cell with a recombinant DNA and/or a recombinant vector coding for (I). The transformed cell is cultivated and the Met-Y-X-Pro-A is recovered from the medium, and cleaved with an IgA protease. The first cleavage prod., a G-CSF deriv. which has the sequence X-Pro-A, is isolated. Also claimed is the recombinant G-CSF itself and medicaments contg. it. USE/ADVANTAGE - The X-Pro-A produced has no N-terminal methionine; such peptides are difficult to synthesise by prior methods. It is a G-CSF deriv. useful for treatment of cancer and leukaemia, in bone marrow transplants, and for treating burns and opportunistic infections affecting patients with weakened immune systems.